No Power - Sanyo PLC-XL51 Service Manual

No Power

This projector provides a function which can be specified a defective area simply by indicating the LEDs. Connect the AC cord
and press the Power button once and then check the LED indication.
- When all of LED indicators are not lighting, the symptom indicates that the primary power supply circuit does not
operate properly. Check the power primary circuit and parts as follow;
AC cord, F601 (Fuse), Power board,
SW902 (Thermal sw.)
- When the WARNING (red) and POWER(red) indicators are flashing, the symptom indicates that the projector de-
tected an abnormal temperature risen inside the projector. Check the air filters and remove the object near the intake
and exhaust fan openings, and wait until the POWER indicator stops flashing, and then try to turn on the projector.
The internal temperature is monitored by sensor ICs, IC8811(Lamp), IC8821 (Panel) on the Main board and IC4831
(Room) on the Temp. board
- When the WARNING indicator lights red, the symptom indicates that the projector detected an abnormality in the
cooling fan operation or in the power supply secondary circuits. Check fan operation and power supply lines, and the
driving signal status.
The P_FAIL signal (Error: L) is sent to pin 215 of IC301<SCALER> when the abnormality occurs inside the projector, and
then the IC301 sends the shutdown signal, LAMPDC_ON, to the power supply circuit to stop its operation, and signal
BALAST_AC to the lamp ballast board via IC4891 and SW901<lamp cover switch> to stop operation of the lamp circuit.
An abnormality occurs on the secondary power supply;
Check power supplies 16V, S6V, S-5V S16V. P_FAIL signal becomes "Low" when the abnormality occurs on any of
the power supply lines.
An abnormality occurs on the fan control circuit;
Check FN901, FN902, FN903, FN904, FN905, and peripheral circuit.
If any of the fans has an error, the fan lock signal drives Q3601 becomes on. As the result, signal FAN_ERR be-
comes Low and is sent to lamp ballast board to stop lamp circuit.
An abnormality occurs on the drive signals;
ON_15.5V signal (Power-on: H) is output from pin 344 of IC301 and 16V supply circuit. ON_5VA signal (Power-on:
H) is output from pin 110 of IC301 and switches Q3582, 5VA supply circuit. 9V_AUDIO supply circuit. ON_3.3V
signal (Power-on: H) is output from pin 92 of IC1802 and switches IC1491, 3.3V_DI and 3.3V_DDA supply circuit.
LAMPDC_ON signal (Power-on: H) is output from pin 89 of IC301 and supplied to the P.F Control IC, IC601, on
the power supply board through Q681, and PC602.
BALAST_AC signal (Power-on: H) is output from pin 413 of IC301 and applied to pin 2 of IC4891 and output pin 4
and then supplied to the lamp ballast board through SW901<Lamp Cover SW>.
CHO_RXD signal at pin 26 of IC301 is applied from the lamp ballast unit. If the abnormality occurred on the lamp
ballast unit, LAMP_DET/CHO_RXD signal becomes "High" and then IC301 shuts down the power supply circuit.
Lamp Cover switch
Make sure that the lamp cover is mounted correctly. If not or
the lamp cover removed, the lamp does not light on for the
safety. Check the lamp cover and lamp cover switch (SW901).
short in normal
SW902 opens when the surrounding temperature of the switch exceeds 100°C.
- 81 -
Troubleshooting
SW901